Research has revealed that keeping your curtains closed during the day can make you more likely to get sick.
The study, which was published in the journal Microbiome, found that sunlight kills bacteria that lives in dust.
Windowless offices are at risk of harbouring harmful bacteria, the researchers warned.
Dr Ashkaan Fahimipour said: “Humans spend most of their time indoors, where exposure to dust particles that carry bacteria, including pathogens that can make us sick, is unavoidable.
“Therefore, it’s important to understand how features of buildings we occupy influence dust ecosystems and how this could affect our health.”

The researchers from the University of Oregon created 11 small model ‘rooms’ with windows that allowed in varying levels of light. After 90 days, the dark rooms had double the number of bacteria than the lighter rooms.
Fahimipour added: “We hope that with further understanding we could design access to daylight in buildings such as schools, offices, hospitals and homes in ways that reduce the risk of dust-borne infections.”
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